United States patent application 2003/0146795 describes an oscillator that comprises switched capacitors and varactors (voltage-dependent capacitors). The switched capacitors provide coarse tuning and the voltage-dependent capacitors provide fine-tuning in a frequency range from 1 to 2 GHz. The oscillator further comprises an amplifier comprising a number of switchable amplifier elements. Each amplifier element is switched on or off depending on the frequency at which the oscillator is oscillating, so as to maintain the transconductance of the amplifier elements within certain limits.